Limit Sugar And Dairy To Reduce Alzheimer’s Risk?

Alzheimer’s disease (AD) has been associated with cardiometabolic disorders such as obesity and diabetes. Does high sugar intake, which may lead to metabolic disorders, increase the risk of AD?

The study: This cohort study involved a retrospective analysis of 37,689 participants (average age of 62 years, 84% white) from the U.S. Women’s Health Initiative - Dietary Modification Trial (WHI-DM) that investigated the associations between sugar intake and AD risk. The WHI-DM consisted of a randomized controlled dietary modification trial held during 1993–2005 with annual survey follow-ups for long-term health outcomes until 2019.

Dietary data were collected using food frequency questionnaires at baseline and at year 1 and included six subtypes of sugar intake (fructose, glucose, galactose, lactose, sucrose, and maltose measured in grams per day).

The follow-up surveys asked the participants whether a doctor had told them that they have a certain disease or complication (e.g., dementia/Alzheimer’s disease or moderate/severe memory problems).

The results: The 25% of participants who consumed the greatest amount of sugar (147 grams/day) had a 19% increased risk of incident AD compared with the 25% of participants who consumed the least amount of sugar (96 grams/day). Approximately 12% (4,586 participants) of the total sample reported having incident AD.

Of the six subtypes of sugar, lactose was significantly associated with AD risk. An estimated increase of 10 grams/day in total sugar intake (about 2.5 teaspoons) was associated with an increase in AD risk of 1.3%. Participants with cardiometabolic disorders had a higher risk of AD than those without.

Several baseline participant characteristics (e.g., race, education, and lifestyle factors) were significantly different across the range of sugar intake.